Controlling the Surface Chemistry of Intermetallic Compounds for Nanoscale Metal Interconnects

Interconnects impose major limits on the performance on integrated circuits during the exponential reduction of feature size of microchips.

The semiconductor industry faces challenges in the metallization of interconnects below the 10 nm half pitch and is looking to alternative metallization schemes to replace copper, the traditional choice for the last 20-years, which no longer meet the conductivity requirements at decreasing length scales.

Binary metals such as nickel-aluminium (NiAl) have been identified as a promising candidate that performs well with respect to resistivity at critical dimensions (sub-10 nm) to replace copper.

However, there are several challenges associated with the instability of these materials regarding surface oxidation, leading to performance degradation.

The objective of CRIME is the in-situ removal of the surface oxide and in-situ passivation of binary intermetallic compounds to prevent surface oxidation at the sub-10 nm half pitch for interconnect applications.

To meet the future size requirements of interconnects, the downscaling of the cleaning and passivation processes from blankets to sub-10 nm half-pitch and the formation of patterned lines, with the aim of sub-7 nm half-pitch, will be performed.This will be achieved through an interdisciplinary approach that combines material science, chemistry, chemical engineering, nanoelectronics, and physics, to test different metal oxide removal and surface cleaning chemistries in combination with organic and inorganic passivation layers in-situ to overcome the formation of an oxide top layer.

The passivation layers will be deposited in the liquid and vapour phase and various analytic techniques will be used to elucidate the surface chemistry and surface reaction mechanisms.CRIME goes beyond the state-of-the-art as the cleaning and passivating process and the downscaling of these processes on NiAl at the nanoscale and for advanced microelectronics nodes has not been previously demonstrated